Saturday, April 20, 2013

CHANGE OF OPTICAL PROPERTIES OF CONTEMPORARY RESIN COMPOSITES AFTER ONE WEEK AND ONE MONTH WATER AGING

This is very interesting and dentist doing composites should take this into consideration. MJ
Available online 10 April 2013

Abstract

Objectives

To compare color and translucency changes after water-aging for 1-week and 1-month in light and dark shades of contemporary polychromatic resin composites.

Methods

Enamel (e) and dentin (d), light and dark (A1 and A4 or equivalents) shades were selected from the composites Enamel-Plus HRi/Micerium, Miris-2/Coltene, IPS Empress-Direct/Ivoclar and Filtek-Supreme/3 M ESPE and light and dark shades from the TPH-Spectum/Densply monochromatic composite. Five disks (d = 10 mm, h = 1 mm) per material, enamel/dentin and light/dark shade were prepared. A colorimetric evaluation, over white and black background, according to the CIELab system was performed just after preparation and after 1-week and 1-month dark water-storage at 37 °C. Color (ΔEab) and translucency (ΔTP) differences were calculated. Results were analyzed by ANOVA and Scheffe's test, paired t-test and linear regression analysis (a = 0.05).
Results:1-week water-aging provided a wide range of ΔΕab values (0.79Filtek(e)/D2 - 5.19 Filtek(d)/A1) and ΔTP values (-2.74 Hri/UD1 - 1.03 TPH/A1). After 1-month water-aging ΔΕab ranged from 1.09 Filtek(e)/D2 to 7.94 Filtek(d)/A1 and ΔTP values from -2.71Hri/UD1 to 1.07 Filtek(d)/A4. Significant changes in ΔΕab between 1-week and 1-month water-aging were noted for Filtek and Miris dentin and Miris light enamel shades. As for ΔTP, significant difference was recorded only for IPS(e)/A4. ΔΕab was significantly correlated with ΔL, Δα, Δb and ΔTP after 1-week and with ΔL and Δα after 1-month aging.

Conclusions

Water-aging caused remarkable color changes, which were material and shade depended. Thirteen out of eighteen of the tested composites exhibited clinically perceptible (ΔΕab > 2.6) color changes even after short water-aging period.

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